1. Field of the Inventions
The present inventions are related to fuel cartridges that may be used, for example, in combination with fuel cells.
2. Background
Many devices are fueled by fuel that is stored in a fuel cartridge. Although the present inventions are not limited to fuel cartridges that are used in conjunction with any particular type of device, fuel cells are one example of a device that may consume fuel stored in a fuel cartridge, and the present inventions are discussed in the context of fuel cells for illustrative purposes only. Fuel cells convert fuel and oxidant into electricity and a reaction product. Fuel cells that employ hydrogen as the fuel and oxygen as the oxidant, for example, produce water and/or water vapor as the reaction product. Fuel cartridges used in conjunction with fuel cells typically store pressurized gaseous fuel or a fuel containing substance, such as a chemical compound, that releases the gaseous fuel in the presence of water or a catalyst.
The inventors herein have determined that conventional fuel cartridges, especially those used in conjunction with fuel cells, are susceptible to improvement. More specifically, the inventors herein have determined that it can be undesirable to store large amounts of gaseous fuel (such as hydrogen) in a fuel cartridge because such storage can raise safety concerns and provide less than optimal energy density. The inventors herein have also determined that, in those instances where fuel containing substances are stored in a fuel cartridge, conventional apparatus for causing the gaseous fuel to be released do not provide precise control over the process. This lack of control can lead to the release of more fuel than is required by the fuel cell, which also raises safety concerns. Thus, the inventors herein have determined that it would be desirable to provide fuel cartridges that facilitate precise control over the conditions associated with the release of gaseous fuel from the fuel containing substance.